Longitudinal Endoleak Behaviour Following Complex Aortic Repair With Branched Devices

Objective: This study aimed to determine the incidence, natural history, outcomes and risk factors of endoleak following branched endovascular aortic repair (BEVAR) for complex abdominal aortic aneurysm (cAAA) and thoracoabdominal aortic aneurysms (TAAAs). Methods: This retrospective, single-centre study enrolled patients with cAAA and TAAA treated with BEVAR. Patients with at least 1 target vessel incorporated using directional branches were included. End points were spontaneous resolution of endoleak detected on completion angiography, 3-year freedom from persistent type I/III endoleak and endoleak-related reintervention. Multivariable Cox regression analyses were performed to identify independent risk factors for type II endoleak (T2EL) and branch-related endoleak (BREL). Results: In a 6-year period, 298 patients underwent fenestrated/branched endovascular aortic repair (F/BEVAR) of which 129 patients (mean age 72 ± 9 years; 62% male) underwent F/BEVAR for 36 cAAA (27.9%) and 93 TAAA (72.1%) with at least 1 directional branch. In all, 458 reno-mesenteric arteries were incorporated using directional branches. Completion intra-operative angiography detected endoleak in 81 patients (64.8%), of which 43.2% demonstrated spontaneous resolution on postoperative computed tomographic angiography. During a mean follow-up of 20.2 ± 19.9 months, 14 branches (3.0%) in 14 patients (10.9%) developed BREL, predominantly type Ic. Freedom from persistent type I/III endoleak and endoleak-related reintervention were 70.6% and 68.5% at 3 years, respectively. Aneurysm diameter ≥80 mm (hazard ratio [HR] 2.76, 95% confidence interval [CI], 1.54-4.95; P < .001), post-dissection aetiology (HR 1.84, 95% CI, 1.02-3.33; P = .043) and accessory renal artery (ARA) ≥3 mm in diameter that was not incorporated or pre-emptively embolised (HR 2.03, 95% CI, 1.11-3.74; P = .022) were identified as independent risk factors for T2EL. Conclusion: Immediate endoleak following BEVAR was common, but a substantial proportion were self-limiting. Type Ic endoleak was the most common type of BREL and the most frequent indication for endoleak-related reintervention. Large aneurysm diameter, post-dissection aetiology and ARA increased risk for T2EL. Clinical Impact Endoleak following branched endovascular aortic repair (BEVAR) was commonly detected on completion angiography; however, immediate intervention was not required after ensuring adequate sealing zones and optimised bridging stent configuration, as 43% demonstrated spontaneous resolution on early postoperative imaging. Type Ic endoleak was the predominant form of branch-related endoleak, highlighting the importance of meticulous attention to target vessel landing zones. When anatomically feasible, incorporation of accessory renal artery ≥3 mm in the repair is recommended; alternatively, pre-emptive embolisation may reduce type II endoleak incidence.